<!--js dom-->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8"/>
    <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
    <title>灯的颜色变化</title>
    <style>
        #container {
            text-align: center;
        }

        #redlight,
        #greenlight {
            display: none;
        }

        #defaultlight {
            display: inline-block;
        }
    </style>
</head>

<body>
<div id="container">
    <img id="defaultlight" src="./images/light.svg" alt=""/>
    <img id="redlight" src="./images/redlight.svg" alt=""/>
    <img id="greenlight" src="./images/greenlight.svg" alt=""/>
</div>
<script src="./js/trafficlights.js"></script>
</body>
</html>
